Novel peptide reagents for imaging damage to collagen structure in histopathology and in vivo - Project Summary_3Helix, Inc.
In this Phase II SBIR proposal, 3Helix Inc. proposes to develop a new user-friendly imaging agent that
can detect denatured collagen in histological tissue section and in vivo animal imaging. Collagen is the major
structural component of nearly all human tissues and organs, providing a sturdy and bioactive framework for
cell growth and tissue formation. Although degradation of collagen takes place during normal tissue
development and maintenance, excessive levels of collagen degradation and denaturation is intricately
involved in a wide variety of diseases including cancer, atherosclerosis, arthritis, osteoporosis, nephritis, and
fibrosis. The denatured collagen molecule is a hallmark indicator of inflammation and tissue injury in these
diseases. However, this indicator is rarely used in biomedical research, due to the lack of reagents or methods
that can readily detect it. The founders of 3Helix, Inc., Drs. Yang Li and Michael Yu, discovered a synthetic
Collagen Hybridizing Peptide (CHP), which can specifically bind to denatured collagen molecules with high
affinity: the CHP peptide is able to form a stable hybridized triple helix structure only with the unraveled
collagen strands but not with intact collagen molecules. The discovery of CHP, and its binding to denatured
collagen, has been patented, published in multiple high impact journals (PNAS, Nat. Commun., ACS Nano).
Because collagen degradation is associated with a wide range of human pathology and injury, CHP’s potential
to detect and monitor disease have drawn overwhelming interests from academics and clinicians, as well as
from industry and major reagent vendors. During the Phase I period, 3Helix developed CHP into a histology
staining reagent for research use, and successfully commercialized it in 2017. The product has been sold to
over 100 users from 11 countries including some of the leading experts from world-renowned institutes.
Despite this success, current CHP requires heating as a pre-conditioning process which complicates
histological study particularly for automated process. Such pre-conditioning is detrimental to comparative in
vivo study. Recent study suggests that dimeric form of CHP is able to detect degraded collagens that a
conventional monomeric CHP cannot detect due to improved affinity made possible by mutivalency. In the
Phase II period of the SBIR grant, 3Helix plans to make significant improvement to the current peptide design
in order to make CHP easier to use in vitro without heat treatment, but more importantly to develop a first-of-
its-kind near-infrared fluorescence (NIRF) probe for in vivo animal imaging. The new design, which is based on
solid preliminary study, involves the dimeric CHP structure comprised of non-self-trimerizing peptide sequence.
In addition to developing the new probe and demonstrating its use in disease detection and monitoring for in
vitro and in vivo use, 3Helix will also produce optimized protocols for i) in vitro assay of degraded collagen in
tissue section as well as for ii) in vivo imaging of mouse disease model. The successful outcome of this project
will open new avenues in basic research, drug development, and medical diagnosis for over 30 different types
of human diseases, including cancer, fibrosis, cardiovascular disease, and arthritis.